Bonding tool, device and bonding method for flexible graphite bipolar plate of fuel cell

Abstract

The invention discloses a bonding tool, device and method for a flexible graphite bipolar plate of a fuel cell, the bonding tool comprises clamping plates, a bag body and a fixing assembly, the two clamping plates are oppositely arranged at an interval, and a filling channel is formed in the first clamping plate; the bag body is elastic and fixedly connected with the first clamping plate, and the filling channel is communicated with the bag body. The fixing assembly is detachably connected with the two clamping plates. The bonding device comprises a plurality of bonding tools. The bonding method comprises the following steps: S1, coating the graphite polar plates with a bonding agent, and respectively connecting the two graphite polar plates with the two clamping plates; s2, oppositely bonding the two graphite polar plates, and fixing the clamping plate through the fixing assembly; and S3, filling fluid into the bag body through the filling channel so as to compress the two graphite polar plates. Compared with the prior art, the bag body is arranged between the two clamping plates, the two graphite polar plates are pressed by filling fluid into the bag body, all parts of the graphite polar plates can be stressed consistently through the bag body, and the bonding effect is guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of graphite plate production methods, and in particular to a fuel cell flexible graphite bipolar plate bonding tool, device and bonding method. Background Art

[0002] Proton exchange membrane hydrogen and oxygen fuel cells are a type of hydrogen fuel cell composed of a stack of bipolar plates and membrane electrodes, where the membrane electrode is the site of electrochemical reactions and the bipolar plate is a channel for providing reaction gases and coolants. Bipolar plates are composed of cathode and anode plates, which can be generally divided into metal plates, graphite plates and composite plates according to the material properties. Due to the material properties of graphite plates, graphite bipolar plates generally use glue to bond the cathode and anode plates together.

[0003] The bonding of bipolar plates must not only ensure that there is no coolant leakage, but also ensure reliable contact between the anode plate and the cathode plate to minimize the internal resistance of the bipolar plate, so the cathode plate and the anode plate must fit tightly together during bonding and curing. However, due to the density deviation of the raw materials of the flexible graphite plate and the extrusion molding characteristics of the flexible plate, the flexible graphite plate is almost inevitably uneven. This leads to the formation of local gaps when the flexible graphite bipolar plates are bonded, increasing the contact resistance between the plates, or requiring more adhesive, causing excess adhesive to overflow, further increasing the plate gap and contact resistance. Summary of the invention

[0004] The purpose of the present invention is to overcome the above technical deficiencies and propose a fuel cell flexible graphite bipolar plate bonding tool, device and bonding method to solve the technical problem in the prior art that local gaps exist during bonding due to uneven graphite plates.

[0005] In order to achieve the above technical objectives, the present invention adopts the following technical solutions: In the first aspect, the present invention provides a fuel cell flexible graphite bipolar plate bonding tool, comprising: a splint, two of the splints are arranged relatively spaced apart, two graphite plates are placed between the two splints, wherein the first splint is formed with a filling channel; a bladder, the bladder is elastic and fixedly connected to the side of the first splint facing the second splint, the filling channel is connected to the bladder; a fixing assembly, the fixing assembly is detachably connected to the two splints, and is used to fix the two splints.

[0006] In some embodiments, the two clamping plates are arranged horizontally, and the first clamping plate is located directly above the second clamping plate.

[0007] In some embodiments, the fixing assembly includes a threaded rod, a fixing nut and a limiting sleeve. Guide holes are correspondingly formed on the two clamping plates. The threaded rod passes through the guide holes of the two clamping plates. The limiting sleeve is sleeved on the threaded rod and located between the two clamping plates. The two fixing nuts are respectively located on one side of the two clamping plates away from the limiting sleeve and are connected to the threaded rod. The fixing nut cooperates with the limiting sleeve to clamp the clamping plates.

[0008] In some embodiments, a heating component is further included, and the heating component is disposed in at least one of the clamping plates.

[0009] In some embodiments, the second clamping plate is formed with a detection channel, and the detection channel is connected to the cooling cavity of the graphite electrode plate.

[0010] In some embodiments, the clamping plate has protrusions and / or grooves corresponding to the graphite plate for positioning with the graphite plate.

[0011] In some embodiments, a pressure sensor is further included, wherein a detection head of the pressure sensor is arranged in the filling channel to detect the pressure in the bladder.

[0012] In the second aspect, the present invention also provides a fuel cell flexible graphite bipolar plate bonding device, comprising a plurality of fuel cell flexible graphite bipolar plate bonding tools, the fuel cell flexible graphite bipolar plate bonding tools share the fixing device, and the clamping plates of the plurality of fuel cell flexible graphite bipolar plate bonding tools are arranged in parallel and spaced apart in sequence and are connected in series in sequence through the fixing assembly.

[0013] In a third aspect, the present invention further provides a method for bonding a flexible graphite bipolar plate of a fuel cell, characterized in that the method comprises the following steps: S1. Apply adhesive on the graphite plates and connect the two graphite plates to the two clamping plates respectively; S2, bonding the two graphite plates relative to each other, and fixing the clamping plate by the fixing assembly; S3. Fill the bladder with fluid through the filling channel to compress the two graphite plates.

[0014] In some embodiments, the step S4 is also included, heating the graphite plate to promote the curing of the adhesive.

[0015] Compared with the prior art, the fuel cell flexible graphite bipolar plate bonding tooling provided by the present invention sets a bladder between two clamping plates, and presses the two graphite plates by filling fluid into the bladder. The bladder can avoid the protruding parts of the graphite plates and fill the concave parts at the same time, so that the various parts of the graphite plates are subjected to consistent force, and the pressing force during bonding can be adjusted in real time to ensure the bonding effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a side view of a fuel cell flexible graphite bipolar plate bonding tool provided by an embodiment of the present invention; Figure 2 The present invention is a flowchart of a method for bonding flexible graphite bipolar plates for fuel cells provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0018] In order to solve the technical problem of poor bonding effect of uneven graphite plates, the present invention provides a fuel cell flexible graphite bipolar plate bonding tool, which can achieve consistent force on various parts of the graphite plate and ensure the bonding effect.

[0019] It should be noted that the flexible graphite bipolar plate bonding tool for fuel cells described in the present invention is used for but not limited to bonding graphite bipolar plates in fuel cells. For the convenience of explanation, in the present invention, only the application of the flexible graphite bipolar plate bonding tool for fuel cells in bonding graphite bipolar plates in fuel cells is used as an example for explanation. The principle of applying the flexible graphite bipolar plate bonding tool for fuel cells to bonding other uneven plates is essentially the same as the principle applied to bonding graphite bipolar plates in fuel cells, which will not be repeated here.

[0020] See also Figure 1 , Figure 1 Schematic diagram of the structure of a fuel cell flexible graphite bipolar plate bonding tool in one embodiment of the present invention. The fuel cell flexible graphite bipolar plate bonding tool includes a clamping plate, a capsule 3 and a fixing component 4.

[0021] There are two clamping plates, namely a first clamping plate 1 and a second clamping plate 2. The two clamping plates are arranged relatively spaced apart, and two graphite plates 9 are placed between the two clamping plates. The first clamping plate 1 is formed with a filling channel 11.

[0022] The bladder 3 is elastic and fixedly connected to the side of the first clamping plate 1 facing the second clamping plate 2, and the filling channel 11 is connected to the bladder 3. It is easy to understand that one end of the filling channel 11 is located on the side of the first clamping plate 1 facing the second clamping plate 2, and is used to communicate with the bladder 3. The other end of the filling channel 11 is used to connect to an external filling device, so the other end is preferably arranged on other sides.

[0023] The fixing assembly 4 is detachably connected to the two clamping plates to fix the two clamping plates.

[0024] In some embodiments, the two clamping plates are arranged horizontally, and the first clamping plate 1 is located directly above the second clamping plate 2 .

[0025] In a preferred embodiment, protrusions and / or grooves corresponding to the graphite plates 9 are formed on the opposite sides of the first clamping plate 1 and the second clamping plate 2, so as to cooperate with the graphite plates 9 for positioning, so that the graphite plates 9 respectively mounted on the two clamping plates can be arranged exactly opposite to each other. It is easy to understand that the protrusions or grooves on the clamping plates corresponding to different graphite plates 9 are also different. Different clamping plates can be used to produce different graphite plates 9.

[0026] In some embodiments, in some embodiments, the second clamping plate 2 is formed with a detection channel 21, and the detection channel 21 is connected to the cooling cavity of the graphite plate 9. A detection gas with a certain pressure is injected into the graphite plate 9 through the detection channel 21, and the bonding effect of the graphite plate 9 is reflected by measuring the air tightness of the graphite plate 9. Similar to the filling channel 11, one end of the detection channel 21 is located on the side of the second clamping plate 2 facing the first clamping plate 1, and is opposite to the interface of the cooling cavity of the graphite plate 9. The port of the detection channel 21 is preferably provided with a sealing ring 5 to avoid air leakage here, which affects the detection of the bonding effect of the graphite plate 9. The other end of the detection channel 21 is used to connect an external gas supply device, so the other end is preferably arranged on other sides.

[0027] In some embodiments, the bladder 3 is a bag-like structure and can be made of rubber. When fixed to the first clamping plate 1, it avoids the protrusions or grooves of the first clamping plate 1. The bladder 3 can be folded to reduce the area it occupies, expands in volume after being filled, and then covers the graphite plate 9, so that each part of the graphite plate 9 is evenly pressed.

[0028] In some embodiments, two clamping plates may be connected with multiple fixing components 4 to obtain a better fixing effect. For example, when the clamping plate is rectangular, a fixing component 4 may be connected to each of the four corners.

[0029] In this embodiment, a plurality of guide holes are correspondingly formed on the first clamping plate 1 and the second clamping plate 2, and a fixing assembly 4 is installed on each pair of guide holes. Each fixing assembly 4 includes a threaded rod 41, a fixing nut 42 and a limiting sleeve 43. The threaded rod 41 passes through the guide holes of the two clamping plates, and the limiting sleeve 43 is sleeved on the threaded rod 41 and located between the two clamping plates to ensure that a certain distance is maintained between the two clamping plates. The two fixing nuts 42 are respectively located on the side of the two clamping plates away from the limiting sleeve 43 and are connected to the threaded rod 41. The threaded rod 41 plays the role of limiting guide, so that the first clamping plate 1 and the second clamping plate 2 can be aligned and slide along the threaded rod 41 while maintaining the alignment. Screw the fixing nut 42, and the fixing nut 42 cooperates with the limiting sleeve 43 to clamp the clamping plate.

[0030] In some embodiments, the bonding tool further includes a heating component 6, and at least one clamping plate is provided with a heating component 6, which promotes the curing of the adhesive 8 by heating. The heating component 6 can be a heating wire, a thermocouple, etc. The heating component 6 can also be provided in both the first clamping plate 1 and the second clamping plate 2 to obtain a better heating effect.

[0031] In some embodiments, the bonding tool further includes a pressure sensor, the detection head of which is arranged in the filling channel 11 to detect the pressure in the capsule 3. On the one hand, it can prevent the excessive pressure in the capsule 3 from damaging the capsule 3 or the graphite plate 9, and on the other hand, it can also adjust the pressure in the capsule 3, that is, the pressing force when the two graphite plates 9 are bonded, to ensure the bonding effect.

[0032] The present invention also provides a fuel cell flexible graphite bipolar plate bonding device, including a plurality of the aforementioned fuel cell flexible graphite bipolar plate bonding tools, each bonding tool shares a fixing device 4. The clamps of the plurality of bonding tools are arranged in parallel and spaced apart in sequence, and are connected in series in sequence through the fixing assembly 4. That is, the first clamp 1 and the second clamp 2 are arranged alternately and spaced apart, and a threaded rod 41 passes through the guide holes of each clamp at one time. A fixing nut 42 and a limiting sleeve 43 are installed at corresponding positions on the threaded rod 41. The fixing nut 42 and the limiting sleeve 43 cooperate to clamp and fix each clamp, and the limiting sleeve 43 maintains an equal spacing between the first clamp 1 and the second clamp 2 of each bonding tool. The present bonding device has a plurality of bonding tools, and can bond a plurality of graphite plates 9 at one time, thereby improving the bonding efficiency.

[0033] In order to be suitable for the bonding device, as shown in the figure, the inlets of the filling channel 11 and the detection channel 21 are arranged on the sides around the clamping plate, rather than on the upper and lower sides.

[0034] See also Figure 1 and Figure 2 , Figure 2 The present invention is a flowchart of a method for bonding flexible graphite bipolar plates for fuel cells provided in an embodiment of the present invention.

[0035] The present invention also provides a fuel cell flexible graphite bipolar plate bonding method, using a fuel cell flexible graphite bipolar plate bonding tool, which includes the following steps: S1. Apply adhesive 8 on the graphite plates 9, and connect the two graphite plates 9 to the two clamps, respectively. That is, the two graphite plates 9 are connected to the first clamp 1 and the second clamp 2, respectively, and the graphite plates 9 are positioned by the protrusions or grooves on the first clamp 1 and the second clamp 2. It is easy to understand that, depending on the bonding process, both graphite plates 9 can be coated with adhesive 8, or only one graphite plate 9 can be coated with adhesive 8.

[0036] S2, bond the two graphite plates 9 relative to each other, and fix the clamps by the fixing assembly 4. Specifically, place the limiting sleeve 43 on the second clamp 2, and pass the threaded rod 41 through the second clamp 2 and the limiting sleeve 43. Then install the graphite plate 9 connected to the first clamp 1 on the threaded rod 41, and the threaded rod 41 limits the first clamp 1, so that the two graphite plates 9 are aligned and fit. After the two graphite plates 9 are initially bonded, screw the fixing nut 42 to clamp the clamp.

[0037] S3. Fluid is injected into the capsule 3 through the injection channel 11. The capsule 3 expands and presses the two graphite plates 9 tightly, so that the two graphite plates 9 are closely attached together, thereby ensuring the bonding effect.

[0038] In some embodiments, the method further includes step S4, heating the graphite plate 9 to promote the curing of the adhesive 8. The graphite plate 9 can be heated by arranging a heating component 6 in the clamping plate. Alternatively, the heating component 6 may not be arranged, but a fluid medium of a certain temperature, such as hot water, may be introduced into the capsule 3 to produce the same heating effect. Alternatively, an external heating device may be used, such as placing the entire bonding tool in an oven for heating.

[0039] In some embodiments, step S5 is also included, introducing a detection gas, such as 50 kPa to 200 kPa nitrogen, into the cooling cavity of the graphite plate 9 through the detection channel 21 to measure the airtightness of the graphite plate 9 to reflect the bonding effect of the graphite plate 9.

[0040] It is easy to understand that the use of the bonding device is similar to that of the bonding tool, except that in step S2, multiple clamps and multiple graphite plates 9 need to be installed together. Then, fluid is added to each capsule 3 and each graphite plate 9 is heated, so the detailed steps are not repeated.

[0041] The specific implementation of the present invention described above does not constitute a limitation on the protection scope of the present invention. Any other corresponding changes and modifications made based on the technical concept of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A fuel cell flexible graphite bipolar plate bonding tool, characterized in that: include: A clamping plate, wherein two clamping plates are arranged relatively spaced apart, and two graphite plates are placed between the two clamping plates, wherein a filling channel is formed on the first clamping plate; A bladder body, which is elastic and fixedly connected to the side of the first clamping plate facing the second clamping plate, and the filling channel is connected to the bladder body; A fixing assembly is detachably connected to the two clamping plates to fix the two clamping plates.

2. The fuel cell flexible graphite bipolar plate bonding tool according to claim 1, characterized in that: The two clamping plates are arranged horizontally, and the first clamping plate is located directly above the second clamping plate.

3. The fuel cell flexible graphite bipolar plate bonding tool according to claim 1, characterized in that: The fixing assembly includes a threaded rod, a fixing nut and a limiting sleeve. Guide holes are correspondingly formed on the two clamping plates. The threaded rod passes through the guide holes of the two clamping plates. The limiting sleeve is sleeved on the threaded rod and located between the two clamping plates. The two fixing nuts are respectively located on one side of the two clamping plates away from the limiting sleeve and are connected to the threaded rod. The fixing nut cooperates with the limiting sleeve to clamp the clamping plates.

4. The fuel cell flexible graphite bipolar plate bonding tool according to claim 1, characterized in that: It also includes a heating component, and the heating component is arranged in at least one of the clamping plates.

5. The fuel cell flexible graphite bipolar plate bonding tool according to claim 1, characterized in that: The second clamping plate is formed with a detection channel, and the detection channel is connected to the cooling cavity of the graphite electrode plate.

6. The fuel cell flexible graphite bipolar plate bonding tool according to claim 1, characterized in that: The clamping plate has protrusions and / or grooves corresponding to the graphite pole plate, so as to cooperate with the graphite pole plate for positioning.

7. The fuel cell flexible graphite bipolar plate bonding tool according to claim 1, characterized in that: It also includes a pressure sensor, a detection head of which is arranged in the filling channel to detect the pressure in the bladder.

8. A fuel cell flexible graphite bipolar plate bonding device, characterized in that: It comprises a plurality of fuel cell flexible graphite bipolar plate bonding tools as described in any one of claims 1 to 7, wherein the fuel cell flexible graphite bipolar plate bonding tools share the fixing device, and the clamping plates of the plurality of fuel cell flexible graphite bipolar plate bonding tools are arranged in parallel and spaced apart in sequence and are connected in series in sequence through the fixing assembly.

9. A method for bonding flexible graphite bipolar plates for fuel cells, characterized in that: The fuel cell flexible graphite bipolar plate bonding tool as claimed in any one of claims 1 to 7 comprises the following steps: S1. Apply adhesive on the graphite plates and connect the two graphite plates to the two clamping plates respectively; S2, bonding the two graphite plates relative to each other, and fixing the clamping plate by the fixing assembly; S3. Fill the bladder with fluid through the filling channel to compress the two graphite plates.

10. The method for bonding flexible graphite bipolar plates for fuel cells according to claim 9, characterized in that: The method further comprises step S4 of heating the graphite plate to promote the curing of the adhesive.

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